The Hessian fly is present in wheat growing areas throughout the U.S., including Indiana. The Hessian fly can survive on alternative grass hosts, and will be waiting to infest a field the next time wheat is planted. When the opportunity presents itself, there is potential for a rapid increase of fly populations as a result of weather conditions or cropping practices that favor survival of eggs and young larvae in the fall. Many fields throughout the U.S. are already empty due to the nationwide drought that occurred this year. It is imperative that we do not jump the gun and still practice the fly-free date and plow fields before planting wheat.
Following the fly-free date. Much of the fall fly population can be avoided by planting after the fly-free date. A low fall infestation often goes unnoticed due to the tillering of the wheat plant The fly-free date is of key importance, even if you plan to use the wheat only for cattle. It is tempting given the open fields early in the season to plant wheat early. This could lead to disastrous consequences. The fly-free date is our main protection to avoid a subsequent infestation by the spring brood. Additionally, it has been shown that following the fly-free date helps reduce other wheat disease problems and reduces winter-kill from excessive growth.
Plowing fields after wheat harvest destroys the fly. The Hessian fly passes the summer in the stubble of the current wheat crop. Volunteer wheat germinates and begins growing just in time for the fall emergence of the Hessian fly. These plants are readily infested resulting in a rapid build-up of the population. Removal of volunteer wheat before the emergence of the fall brood greatly reduces the insect reservoir for a spring infestation.